Yes, generally it is recommended to use concrete when installing a fence. Concrete helps to secure the fence posts in place and provides a stable base for the rest of the fence. Without concrete, the fence posts may not be properly anchored and may shift or lean over time. This can cause the fence to become unstable and potentially even collapse. Using concrete also helps to prevent the fence posts from rotting, especially if the soil is damp or prone to flooding.
There are some exceptions to this rule. In certain tropical climates, wood fence posts may rot faster if they are surrounded by concrete due to the high moisture content in the air. In these cases, it may be better to use an alternative method for securing the posts such as using metal brackets or building a dry well around the base of the posts.
Overall, it is important to follow the manufacturer’s recommendations and local building codes when installing a fence to ensure that it is properly secured and meets all safety standards.